SU834257A1 - Charge for making coal lining blocks - Google Patents

Description

The invention relates to elektrolita- ² VESKO obtaining electrolytic aluminum melts and can be used in the electrode industry for yzgotovpenii carbon blocks used for lining the sidewalls of electricity, the electrolytic Lieser method of producing aluminum in non-ferrous metallurgy, and when the lining works in other industries. ^h

Known charge £ 1 ^ dsh bottom hearth, including, weight,%:

Foundry Coke Artificial Graphite Coal Tar

Organic Plasticizing Additive

T ermoanthraiit

Ugolnby lining blocks made according to the composition of the known charge, ob30-35

fall in insufficient operational durability. Coal coke included in the mixture has low chemical resistance in the melt of electrolyte, metals, and especially when interacting with alkali metals. For this reason, coal lining blocks under the influence of an aggressive environment are destroyed and prematurely decommission important process equipment at aluminum smelters.

, Closest to the proposed technical essence and the achieved result is the composition ^ 2] hearth Mass for lining of aluminum electrolytic cells, including weight. %: Artificial Graphite

Thermoanthracite Coal tar pitch

Coal lining blocks are chemically resistant according to this composition, but have 45-65

15-35

18-24 yields insufficient mechanical compressive strength.

The bulk of the mass contains artificial graphite, which is an expensive and scarce material, and its low electrical resistance sharply increases the electrical conductivity of coal lining blocks. Coal blocks with low electrical resistance, used for lateral lining of electrolyzers, lead to increased irrational loss of electricity when receiving aluminum.

The chain of the invention is an increase in mechanical strength and a decrease in the electrical conductivity of coal lining blocks while reducing their cost.

, The goal is achieved in that the mixture, including thermoanthracite, artificial graphite and coal tar pitch, additionally contains waste from the graphitadia electrode furnaces

5-20

15-30 industry in the following ratio of components, weight.

Artificial Graphite

Coal tar pitch

Waste from graphite furnace and electrode industry Thermoanthracite

Waste from graphite furnace and electrode industry has the following composition, May. %:

Graphite

Silicon Carbide Silicon Oxide Example. For

5-30

Rest

30-50

20-40 10-30 of obtaining coal lining blocks use thermoanthracite according to GOST 4 794-75, artificial graphite according to GOST 4420-71, waste from graphite and electrode industry and coal tar pitch according to GOST 10200-73.

Thermoanthracite has the following properties:

True specific gravity, g / cm ’Electrical resistivity, Ol μg / m

1-87

960.0

Wastes from graphite furnace and electrode industry have: true specific gravity 2.3 g / SKG *, specific _ electrical resistance 7454 Ohm mm "/ m.

834257 4

Artificial graphite has the following properties: a true specific gravity of 2.23 g / cm ·, a specific electrical resistance of 170.00 Ohm.mm ^ / m.

The following are the properties of coal tar pitch:

Softening Point ° C 68.0

The yield of volatile substances,% 52.0 ₁₀ Coal tar pitch contains carboids 2 7.0) asphaltenes 30.1; maltens 42.9.

Thermoanthracite, artificial graphite and a waste furnace ₁₅ grafitaiii electron native industry pulverized to obtain a fraction (-10 + 0) mm and make up for the charge coal lining blocks.

In the table. 1 shows the composition of shih — ²⁰ thou for the extreme and optimal content of components.

Table 1

Material The content of components, weight. % 1 2 3

Thermoant

raiitis 20 55 75 Artificial Graphite 20 10  5 Waste from graphite furnace and electrode industry thirty fifteen 5 Coal • pitch thirty 20 fifteen

If necessary, the particle size of thermoanthracite, artificial graphite and waste from furnaces of graphite and the electrode industry is increased to ⁵⁰ 25-30 mm.

The mixture of each composition is poured into a paddle-type mixer with electric heating with a capacity of 10 l and mixed at 125-130 ° C for 60 minutes. The hot mass from the mixing machine is loaded into a drum-type multi-unit cooler and processed by rotation for 25-30 minutes.

A pre-chilled mass up to 95-100 ° C is loaded into a container of a hydraulic press with a force of 100 tons and stitched through a mouthpiece with a 60 mm diameter calibration hole. ₅

Compressed billets are cooled to 25-30 ° C. they are cut into pieces 200 mm long, loaded with a pouring from coal coke into a metal container and placed in a chamber of an industrial kiln. Firing is carried out for a duration of 360 hours to a maximum temperature in the gas phase under the roof of the chamber 1250-1300 ^r C. 15

After firing, they are analyzed to determine the mechanical strength during compression. For the proposed composition (2), the mechanical strength of the test samples is 1.5 times larger than the known one, and the electrical resistivity is increased 7 times.

The composition of the charge according to the proposed invention provides the expansion of the raw material base and reduce the cost of production of coal lining blocks by 25-30%.

Claims (2)

(54) CHARGES FOR THE MANUFACTURE OF COAL FABRIC BLOCKS 38 lack of mechanical compressive strength. The composition of the mass in large quantities contains artificial graphite, which is an expensive and scarce material, and its low electrical resistance dramatically increases the electrical conductivity of coal lining blocks. Coal blocks with low electrical resistance used for lateral lining of electrolyzers lead to increased irrational loss of electricity at getting aluminum. The purpose of the invention is to increase the mechanical strength and reduce the electrical water content of the angular lining blocks while reducing their cost. The goal is achieved by the fact that the charge, including the thermoantra 1PC, artificial graphite and coal tar pitch, additionally contains waste from the graphitization furnaces of the electrode industry in the following ratio of components, weight. %: Artificial graphite. 5-20 Coal-tar pitch 15-ZO Otstsody from the graphitization furnaces of the electrode industry 5-30 Thermo-anthracite The rest The graphite-metal furnace waste from the electrode industry has the following composition, May. %: Graphite-5O Silicon carbide 2O-40 Silicon oxide 1O-30 Example. Thermal anthracite according to GOST 4794-75, art graphite according to rOGT 442 & -71, waste from graphitization furnaces of the electrode industry and coal tar pitch according to GOST 102 OC-73 are used to obtain coal lining blocks. Thermoanthracite has the following properties: №: mud specific gravity, g / cm1-87 Electrical resistivity. Ohm MivT / M960.0 Waste from graphite carbon furnaces The electrode industry has: IK; A thin weight of 2.3 g / cm, an electrical resistivity of 7454 ohm mm “/ m. Artificial graphite has the following properties: a true specific weight of 2.23 g / cm, a specific electrical resistance of 170.00. Below are the properties of coal tar pitch: Softening temperature ° С 68.0 Volatile matter yield,% 52.0 Coal tar pitch contains carboids 27.0, asphaltenes 30.1; Maltese 42.9. Thermoanthracite, artificial graphite and waste from the graphitization furnaces of the electrode industry are crushed to obtain a fraction (-1SI-0) mm and make up the charge for coal footer box blocks. in tab. Figure 1 shows the composition of the mixture for the extreme and optimal content of the components. Table 1 Content of components, Material weight. % If necessary, the particle size of thermoanthracite, artificial graphite and waste from furnaces of the graphite industry of the electrode industry increase to 25-30 mm. The mixture of each composition is poured into a paddle type mixing machine with electric heating with a capacity of 1 O p and mixed at 125-13 O S for 6 O min. The hot mass from the mixing machine is loaded into the mixocool drum drum type and processed by growing for 25-30 minutes. The pre-cooled mass up to 95-10b ° C is loaded into a hydraulic press container with a force of 100 tons and stitched through a mouthpiece with a 60mm diameter vibrating hole. The pressed billets are cooled to 25-30 ° C. metal container and set in the chamber of an industrial kiln. Calcination is carried out for a period of 360 hours up to the maximum temperature in the gas phase under the roof of the chamber 1250-1300 0. After calcination, it is analyzed to determine the mechanical compressive strength and electrical resistivity. T a bl and c a 2. The data given in Table 2 shows that for the samples according to the proposed composition, high mechanical strength and electrical resistivity are observed. The CPU of the proposed composition (2) the mechanical strength of the test pieces compared to the known one is 1.5 times greater, and the electrical resistivity increases by 7 times. The composition of the mixture according to the invention provides for the expansion of the resource base and reducing the cost of production of coal lining blocks by 25%. Claims for fabricating coal lining blocks, including thermoanthracite, artificial graphite and coal tar pitch, characterized in that, in order to reduce mechanical strength and reduce electrical conductivity while reducing the cost of production, it also contains waste from the graf furnace of the electrode industry at the next the ratio of components, weight. %: Artificial graphite 5-20 Coal tar. 15-30 Waste from furnaces of graphite metal electrode industry 5-30 Thermo anthraciteOther Sources of information taken into account during the examination 1. Author's certificate of the USSR No. 395504, cl. C 25 C 3/06, 1972. 2. USSR author's certificate number 316747, cl. С 25 С 3 / О8, 197О.